Apparatus for applying abrasive to plate glass grinding mechanism



Feb. 15 1927.

v G. w. oAKEs APPAR'USk FOR APPLYING ABRASIVETO PLATE GLASS4 GINDING NIECIIAIUSMv Filed April 18, 1922 mwen/70e.

Patented Feb. 1927.

'Uni-'r' GEORGE :1* ci e A 4v'strass CoMPANYgn ooaronari-oirer rninsiiviinia;

Application led AprilV 18, 1922. 'Serial Nl'c. 555,378,.-

The invention relates to an apparatus'or handling, grading and applying abrasive material, such as. sand to machines used in grindingvplate glass. The objects of the invention are, (l) to improvev the linitial grind-ing operationV so that a fiat uniform surface is securedmore quickly and danger of breakage reduced,'(2) to reduce the Wear upon the pump parts and those portions of the grader exposed to the. action of. the abrasive, (3) to avoid the danger oclog.-V ging the. grader and still secure athickmixg.v ture of. the abrasive in the early stages. of grinding and, (4;). to permit .the use of a grader of'smaller siz'ethan `would otherwise bepossible. Y v:` 1

Heretofore it .has been customary to.sup. ply they new or green sand for eacligrinding operation .to the sump. and then pump the. mixture up into the grader Aand supplyfitto, the grinder in grades whichare progressive'- ly liner as the grinding progresses.; In vitol-i lowingV this procedure, difficulty is vexperienced in securing av suiiciently thick mixture for' givingthe .best results. in .the-5 initial grinding, and a certain amount of the wornl sand is. carried along with .the newfsharp .sand thus interfering .to acertain Vextent in this irst roughfgrinding. A`AThe samegresult occurs where the new lsand in measured amount is supplied directly to the grad'eratV the beginning of the grinding operation i-nstead of to the sump.

The practice hasalso been followed Lof.. supplying the new sand to a separate sump, andthen pumping it to a lsupply.hopper which dischanges to the table as the grinding progresses until enough new sand is supe plied for the grinding operation, after which the grinding iscontinued using Vthe grading apparatus vin the usual way. This procedure alsohas the disadvantage ot sup.

plynga mixture which i's not sutiiciently thick` and involvesthe use of an extra pump and Yconduits incident toV the/circulation of the abrasive to the supply hoppen in V carrying out my process these difficulties are avoided ,by using a new sand -hop@` per. which( ,discharges directly to` the .table and to whichy the new org'reen sandf is supplie'di'romabove byffmeans oit' la bucket or telpher;` An amount ot sandL is supplied to the hopper which is sufficient orthegrind: ing operation 'before-such operation starts.- This sand is then Washed to the table in a f Referring. first very thick mixture and the rough vgrinding .completed .by the use ofthismixture before the abrasive'from the'.` grader is brought in.-v to service for carrying out the iiner grinding. Thei'elatively t-hick mixture thus suppliedA cushions the runners andf tends to prevent breakage, and because ci' ythe sharp quality. of the new sand, the' .high spots on the table are lrapidly. .cut away.l The sharp, new'sandis in this wayibrought into service immediately withoutpassing through theV grader and without imposing' any .weary on thejpump or Yother grader parts, andtnone offth'e-V liner grades Vin i the graderiare disturbed orV carriedy to Vthe. table. prematurely.

, One; embodiment of the inventionis illus-y tratedin'the accompanying drawings whereratus vwhich. preferably employedv with certain of the: par-ts there-of in'se'ctions, and

sand hopper.

oi partsasshownjinjFig. 1`, 1 is adgla'ss 'Figure 1'1is alsideelevationofV the appa-` W. oAKEs, oFcaYsTAL CITY, iuissonai, assi-.enea rirrsuneiiriiarn" VFig. :Zis ajlverticalsection throughthenew4 i to the' general arrangement i grinding .tableiwhichmayjbefoii. anyiiap-j 'i proved type and' driven .inthe usuali; manner; 2 is oneY of the runners'suchas. is commonly .,en'iplo'yefdN in. the Y grinding of plate glass ;.1. 3Y.fis .a trough Alying .beneath .and enl...

circling the outeredge. of .the grinding ptas bleV and. adapted lto receivefthe. waterandl.

abrasivetroin such...table .during the grind-l ing operation.; .t1-is asum'p ori'collectingreceptacle int'o Awhich thegininture oi` sand aiid Water from' the troughl; runs by vgr.avityf;5 is a .grader into. whichgtheinizture of sand and water from` the sump '4, is lifted. by Vmeansot the pump @driven from the motor y 7:; 81s a trough forconducting the mixture of .sand and Water. from thef-gradertothe i grinding. table; 9 is a new rsand-hopperv pro-1 vided withan outlet pipe 1() also leadingto the grinding table and `11`is-a bucket. carried. byV an overhead crane,v not shown, ordeliihV ering neusand tothehopper. 9.

g The grader V5 :is preferably of thejtype shown inithefBechtel Patent #1,089,895, yissuedv March 1.0511914', although some 'other typeV of' grader `might. bev substituted, y if "de-` sired. Tliisgraderhas anjovertlowjpipe 12 through Vwhich any Ymudand sand too` fine for use is carried to the sewer `13 or. some Y n other v.waste receptacle.l vThe abrasive inthe tank is graded by the upward'flow ofwater produced by the pump 6, the coarser grades lying at the bottom of the tank and the grades becoming finer andk liner from the lower levels tothe higher levels. The different grades are withdrawn through the pipes 14, and 16,-the finer grades being withdrawn through'the pipe 16 which has its inner end in the form of a flexible tube adjustable vertically. Intermediate the ends of the tank is an overflow 17 which Vdischarges to the pipe 18 leading back to the trough or gutter 3. i In operation those grades which are not being used are returned to the sump, this being accomplished v. by having those of the pipes 14, 15 and 16 which are not in use discharged to the box 19 and thence to the sump through the pipe 20. This particular' grader constitutes no part of the present invention and reference' is made to the Bechtel patent heretofore referred to for a showing of the details of construction and the methodof operation.

The construction of the sand hopperY 9, to which the new or green sand is supplied, will be seen by reference to F ig. 2 which shows the hopper in section. A screen 21 isp-r0- Vvided at the bottom of the hopper and through this SCIGEH Projects a' washout pipe of the hopper. l water pipe 24 which is directed downwardly 'y through the discharge pipe 10.

22. This pipe is connected with a source of water supply and has a plurality of upwardly directed discharge slots 23 which direct the water upwardly along the sides Farther down is another The two pipes 22 and 24, together constitute ank effectivef means for undermining and wash- Y ing out the contents of the hopper.

The methody of operation is as follows:- A measured quantity ofrnew sand sufficient to carry out the complete grinding operation is supplied to the hopper 9 by means of the bucket 1'1. The rotation of the grinding table now being started, a flow of water is admittedthrough the washout pipes 22 and 24 to' carry the sand down through the' pipe `10 onto the table, the runners at this time being raised slightly above the surface of the glass. Only sufficient water is supplied through the pipes 22 andV 24 to properly wash out the sand and. give a relatively thick mixture. As soon as this mixture covers the surface of the glass on the table, the runners are gradually lowered, the layer of sand onfthe table acting as a cushion for the runners and tending to avoid the dangerv of breakage, such as sometimes occurs when the runners come to'o sharply in Contact with: the glass. The rough grinding action is continued until' the sand is exhausted from the hopper 9' and a` fairly fiat uniformsurface is securedV upon the glass'. The time required for this action varies, but ordinarily runs from 1Q to 15 minutes.A During this timethe sandE is fed on continuously and due to the sharp character of the sand the high-spots are rapidly cutaway anda flat surface secured.

During this' application of the new sand for the rough grinding, the mixture of sand and water `vwhich is thrown from the table Vis collected inthe sump 4 and pumped up there will be a collection in the grader of a sufficient quantity of the finer grades to finish 'the grinding operation. As soon as the tank 9-is emptied, the supplying of sand from the grader 5 to the table through the trough 8 is started. The first grade is the coarsest from the pipe 14, after which finer and finer grades are Vsupplied from the pipes 15 andr 16 until the grinding with the sand is completed and the glass is ready for the final smoothing operation with the emery which is applied in thel usual way.

' The application of the sandv in thev man-- ner above' set forth facilitates the speed of grii'iding as comparedV with Vthe Vuse of a grader, such as the grader 5 alone. This is due to the fact as heretofore referred to, that all of the sand supplied from' the hopper 9 in the initialoperation is sharp, new sand which has an effective cutting action and tov the fact that the mixture suppliedl is thicker than any mixture which it is practicable -to supply from" the grader 5. 1f it were attempted to secure as thick a mixture from' the grader 5 alone for the coarse grinding, the grader would become clogged upY and becomev ineffective to properly separate the grades. Furthermore, a large l amount of the. finer grades would be entrapped with the coarse material` and interfere'with thecutting action of the coarse material when applied to the. table. The thicker' mixture as supplied from the tank 9V not only speeds up the grinding action as compared with a thinner mixture, but also serves as a cushion in letting the runners down, permitting the lowering of the runners more quickly and with less care and reducing the danger of breakage. Since the new sand applied from the hopper 9 tothe table,rinv the first instance does not pass through the grader preliminary to its use, there is not the wear'upon the grader and pump parts as would be the case if the new sand weresupplied to the sump-4 and carried through'the grader before its application to the table. This is an important feature in the upkeep of the grader since the abrasive rapidly wears out( the piping and pump parts, requiring frequent replace- "dient also permits of the use Yof a smaller grader than if the tank 9 were not used, since the Work thrownV upon the grader is` `much less, due to the fact that thecoarse' new sand does not have to be taken care of in the grader before its application to the Y grinder. A further advantage vof the sys- VVabove the machine,v Washing such abrasive tem resides in the fact that the system adapts itself to the use of ameasuredquanf tity of sand for each side groun d,Which quantity is very easily and .convenientlyl measured out and supplied by Vmeans of the telpher bucket. Other advantages incident to the'method and apparatus Will be readily apparent to those skilled in the art.

.What I'claim is: c l. The lmethod `of applying sand to'a grinding machine which consists in collecting a measured quantity of new abrasive in a solid mass in a supply hopper located directly to the table in an ungraded' condi-V tion by supplying Waterthereto sufficient tol L ,Y

provide a relatively thick mixture, rough f* grinding'with such mixture, collecting the abrasive and Water from thek machine and supplying them to .a 1 grader, and thereafter regrading 'and reusing the v abrasive.

2,111 combination in grinding apparatus, j

a grinding machine including a table, aA

supply hopper above the machine having an outlet leading directly tothe table,.,a car-v abrasive fromthe hopper to the table ina .Y

relatively thick mixture, agrader 'also 10- cat-ed above the machineA having Y outlet means leading to the table, a sump in lWhich the mixture of abrasive and Water from the Y `table is collected, and elevating means for supplying the mixture inthe sump to the grader. Y

In testimony whereof, I vhave hereunto subscribed -myname this 15thV day vof April,1 l

GEORGE W. oAKn-s. 

